Female connectors or F-connectors are widely used in conjunction with cable television systems. Such connectors typically have an outer non-conductive housing for an electrically conductive connector in the form of a spring clip pin having contact fingers adjacent a hole in the end of the housing for receiving the end of the center conductor of a coaxial cable. passed through a hole in the housing. The opposite end of the spring clip is extended through the other end of the housing for connection to components located in a metal housing for a cable splitter or other components.
The United States patent to Tang U.S. Pat. No. 6,071,144 is directed to a hermetically sealed F-connector which employs the basic connector configurations of a clip pin conductor mounted within the connector body. The clip pin makes an electrical connection with the end of a central conductor of a coaxial cable extended through the top of the body to make contact with spring clip fingers. The opposite end of the clip pin is an extension passing through the bottom end of the housing for connection with components located inside the housing for a coaxial cable splitter, or other similar device. In the device shown in the Tang patent, the non-conductive caps surrounding the spring clip connector are placed inside a brass housing, when then is connected to the cable splitter box by means of external threads on the brass housing. There is nothing in the Tang patent, however, directed to the problem of conveying voltage surges through the connector, from the coaxial cable to components located within the housing with which the connector is used.
A problem, however, exists in conjunction with cable television systems, or similar systems, with respect to electrical surges which may take place in the incoming coaxial cable. If such a surge hits the circuitry inside the cable splitter box (or similar circuit), it is possible to damage the circuit and cause failures. Often, these failures are catastrophic. Consequently, if no surge protection device is used in conjunction with the F-connector of the type shown in the Tang patent, the surges are conducted directly through the connector to the sensitive components.
The United States patent to Martzloff U.S. Pat. No. 3,863,111 discloses the use of a polycrystalline varistor surge protector device for VHF signal lines. The device of this patent employs a connector with a housing attached to it containing the polycrystalline varistor and a conductive spring. The spring is configured to provide proper mechanical positioning of the varistor, and to provide an electrical inductance in series with the varistor to prevent capacitive loading of the protected signal line. Signals exceeding a predetermined voltage are shunted through the varistor to the housing.
The United States patents to Kawanami U.S. Pat. No. 4,509,090; Chaudhry U.S. Pat. No. 5,724,220; and Pagliuca U.S. Pat. No. 5,953,195 all are directed to relatively expensive and somewhat complex gas discharge tubes interconnected in various ways into a circuit for providing surge protection, or operating as lightning arresting structures. As is readily apparent from an examination of the disclosures of these patents, the gas discharge tubes which are employed for the surge protection function necessarily must be added elements to the circuits with which they are used.
The United States patent to Nelson U.S. Pat. No. 3,274,447 is directed to a coaxial cable lightning arrester structure. In the device of Nelson, a xe2x80x9cTxe2x80x9d is made as a connection to the coaxial line, with a projection from the T extended toward an adjustable prong which establishes the width of a spark gap. The adjustable prong, in turn, is mounted in a metal housing which is grounded. Thus, in the event a surge takes place in the coaxial cable with which the device is used, a spark extends from the coaxial xe2x80x9cTxe2x80x9d to the adjustable pointer and is dissipated. A problem with this device, however, is that it necessarily involves an additional structure which must be built into or connected to a coaxial line by means of appropriate couplers; so that additional components, resulting in added bulk and expense, are necessary in order to utilize the surge protection feature of the patent.
Accordingly, it is desirable to provide a surge protection or spark arrest for utilization in conjunction with an F-connector for a coaxial cable, which is inexpensive, simple to install and use, and which does not require a modification of other components in the system with which it is used.
It is an object of this invention to provide an improved coaxial cable F-connector.
It is another object of this invention to provide an improved coaxial cable F-connector with a surge protection feature.
It is an additional object of this invention to provide an improved coaxial cable F-connector with an integral surge protection component.
It is a further object of this invention to provide an improved F-connector for a coaxial cable including an integral surge protection or spark transfer extension integrally formed with the other components of the F-connector.
In accordance with a preferred embodiment of the invention, a female connector or F-connector for a coaxial cable is housed in a main housing member made of electrical insulating material. The main housing member has a top, with a centrally located hole forming an input port for the center conductor of a coaxial cable. The housing has an open bottom. A cap made of electrically insulating material also has an open end and a closed end; and a centrally located slot is formed in the closed end. The main housing member and the cap have interrelated parts, which are used to secure the open end of the cap to the open end of the main housing member to hold an electrically conductive spring clip pin located substantially along the central axis of the main housing member and the cap. The spring clip pin has opposing spring-biased contact fingers located for receiving the end of the center conductor of a coaxial cable passed through the hole in the top of the main housing member. The pin also has a contact extension, which passes through the slot in the cap, for providing electrical contact to the spring clip pin. The spring clip pin further has a conductive projection oriented at substantially 90xc2x0 to the central axis of the main housing member and the cap (and, therefore, of the spring clip pin). This conductive projection extends through an aperture in one of the main housing member or the cap to terminate at, or slightly beyond, the external surface of the main housing member or cap for forming a spark gap with the metal housing, into which the F-connector assembly is located.